Statement A: In , the orbital dipole due to the lone pair is in the same direction as the resultant dipole moment of the bonds. In , the orbital dipole is in the opposite direction to the resultant dipole moment of the bonds. Thus, dipole moment of is higher than . Statement A is incorrect.
Statement B: is a linear molecule ( hybridization). The two bond dipoles are equal and opposite, so they cancel each other out, making the net dipole moment zero. Statement B is correct.
Statement C: has 18 electrons. Its bond order is also has 18 electrons and its bond order is 1. Statement C is correct.
Statement D: In the Lewis structure of ozone ( ), the central oxygen atom forms one double bond and one single bond and has one lone pair. Formal charge . Statement D is incorrect.
Statement E: is an odd-electron molecule (17 valence electrons). The nitrogen atom has only 7 electrons in its valence shell, so it does not satisfy the octet rule. Statement E is incorrect.
Therefore, only statements B and C are correct.